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1.
J Am Chem Soc ; 146(20): 13748-13753, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38722207

RESUMO

We report a highly diastereoselective synthesis of polysubstituted bicyclobutanes possessing up to three stereodefined quaternary centers and five substituents. Our strategy involves a diastereoselective carbometalation of cyclopropenes followed by a cyclization to furnish the bicyclobutane ring system. This straightforward approach allows for the incorporation of a diverse range of substituents and functional groups, notably without the need for electron-withdrawing functionalities.

2.
J Comput Chem ; 45(12): 827-833, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38135482

RESUMO

The Superatom Molecular Orbitals (SAMO) in fullerene derivatives are of great interests which gives a wide basement for many electronic applications. In this work, the Density Functional Theory reveals the SAMO states of endohedrally doped C80 derivatives with Li, Sc, Mn, Ti, Ca, Fe, and Co atoms in molecular and periodic structures. The choice and position of metal atoms in endohedrally doped C80 derivatives largely affects the orientation of SAMO energies and wavefunction distributions. Among various derivatives, the Co-substituted C80 constitutes the lowest SAMO energy. The charge transfer study infers the influence of metal atoms inside the cage on SAMO energies. At higher energies, pz-, 2s-, and pxy- SAMO bands have been overlapped with higher dispersion bands which depict the increased intermolecular interaction in delocalized bands causing a larger dispersion. These results give new insights for future studies on lowering SAMO energy nearly to the fermi level in higher fullerenes.

3.
Phys Chem Chem Phys ; 26(9): 7808-7820, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38375616

RESUMO

In this study, we adopt density functional theory (DFT) to investigate the structural and electronic properties of monolayer and bilayer 2-D porphyrin sheets (PS) of covalent organic frameworks (COFs) upon interaction with Li atoms as an electrode material for Li-ion batteries. Based on their mechanical properties, our systems exhibit remarkable stability. The adsorption of Li at various sites in the monolayer, including over and between the bilayers of PS, is investigated. Our results indicate that Li at site S3 has the highest adsorption energy, and Li is energetically preferred to intercalate within the bilayer rather than monolayers due to its high adsorption energies. Notably, the charge transfer remains consistent for both systems. The density of state distribution, charge density difference plots, spin density and the band structure results show that the PS has high electrical conductivity. Additionally, the reaction potential was carried out, and the negative reaction potential results demonstrate that the system undergoes a reduction reaction. The resultant theoretical capacity and the open circuit voltage highlight that the PS materials of COFs are an important step for use in the next generation high-performance lithium-ion batteries.

4.
Angew Chem Int Ed Engl ; 63(31): e202407602, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-38763909

RESUMO

Neighboring group participation, the assistance of non-conjugated electrons to a reaction center, is a fundamental phenomenon in chemistry. In the framework of nucleophilic substitution reactions, neighboring group participation is known to cause rate acceleration, first order kinetics (SN1), and retention of configuration. The latter phenomenon is a result of double inversion: the first one when the neighboring group displaces the leaving group, and the second when a nucleophile substitutes the neighboring group. This powerful control of stereoretention has been widely used in organic synthesis for more than a century. However, neighboring group participation may also lead to inversion of configuration, a phenomenon which is often overlooked. Herein, we review this unique mode of stereoinversion, dividing the relevant reactions into three classes with the aim to introduce a fresh perspective on the different modes of stereoinversion via neighboring group participation as well as the factors that control this stereochemical outcome.

5.
J Phys Chem A ; 127(39): 8126-8132, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37733633

RESUMO

Understanding superatom molecular orbital (SAMO) states in fullerene derivatives has been in the limelight ever since the first discovery of SAMOs owing to the fundamental interest in this topic as well as to the possible applications in molecular switches and other organic electronics. Nevertheless, very few reports have been published on SAMO states of larger fullerenes so far. Using density functional theory, we attempt to partially remedy this situation by presenting a study on SAMO states in C82 and its Ca and Sc endohedrally doped derivatives, comparing results with previous relevant findings for C60. We find that C82 possesses higher SAMO energies compared to C60, as associated with the symmetry of the molecule, and that endohedral doping leads to energetically favorable side positions of Ca and Sc inside the C82 cage. Among the two, Sc@C82 has more stable SAMO states compared to Ca@C82 as reflected by the shift in the density of states, while the charge states are found to be similar. In the case of the monolayer form, the pz- and 2s-SAMO orbitals overlap with the nearest neighbors, causing parabolic band dispersion with the formation of near free electron states and that the SAMO state energies move closer to the Fermi energy compared to the related molecules. These findings provide promising information about the distribution of SAMO states in C82 fullerene, which can be further relevant in studies of SAMO states of higher fullerenes and for coming applications of these systems.

6.
J Neuroinflammation ; 19(1): 10, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34991629

RESUMO

BACKGROUND: Astrocytes are the most numerous glial cell type with important roles in maintaining homeostasis and responding to diseases in the brain. Astrocyte function is subject to modulation by microRNAs (miRs), which are short nucleotide strands that regulate protein expression in a post-transcriptional manner. Understanding the miR expression profile of astrocytes in disease settings provides insight into the cellular stresses present in the microenvironment and may uncover pathways of therapeutic interest. METHODS: Laser-capture microdissection was used to isolate human astrocytes surrounding stroke lesions and those from neurological control tissue. Astrocytic miR expression profiles were examined using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Primary human fetal astrocytes were cultured under in vitro stress conditions and transfection of a miR mimic was used to better understand how altered levels of miR-210 affect astrocyte function. The astrocytic response to stress was studied using qPCR, enzyme-linked immunosorbent assays (ELISAs), measurement of released lactate, and Seahorse. RESULTS: Here, we measured miR expression levels in astrocytes around human ischemic stroke lesions and observed differential expression of miR-210 in chronic stroke astrocytes compared to astrocytes from neurological control tissue. We also identified increased expression of miR-210 in mouse white matter tissue around middle cerebral artery occlusion (MCAO) brain lesions. We aimed to understand the role of miR-210 in primary human fetal astrocytes by developing an in vitro assay of hypoxic, metabolic, and inflammatory stresses. A combination of hypoxic and inflammatory stresses was observed to upregulate miR-210 expression. Transfection with miR-210-mimic (210M) increased glycolysis, enhanced lactate export, and promoted an anti-inflammatory transcriptional and translational signature in astrocytes. Additionally, 210M transfection resulted in decreased expression of complement 3 (C3) and semaphorin 5b (Sema5b). CONCLUSIONS: We conclude that miR-210 expression in human astrocytes is modulated in response to ischemic stroke disease and under in vitro stress conditions, supporting a role for miR-210 in the astrocytic response to disease conditions. Further, the anti-inflammatory and pro-glycolytic impact of miR-210 on astrocytes makes it a potential candidate for further research as a neuroprotective agent.


Assuntos
Astrócitos/metabolismo , Inflamação/metabolismo , MicroRNAs/metabolismo , Acidente Vascular Cerebral/metabolismo , Animais , Células HeLa , Humanos , Inflamação/genética , Microdissecção e Captura a Laser , Camundongos , MicroRNAs/genética , Acidente Vascular Cerebral/genética
7.
Microb Pathog ; 159: 105133, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34390768

RESUMO

Zoonotic viruses originate from birds or animal sources and responsible for disease transmission from animals to people through zoonotic spill over and presents a significant global health concern due to lack of rapid diagnostics and therapeutics. The Corona viruses (CoV) were known to be transmitted in mammals. Early this year, SARS-CoV-2, a novel strain of corona virus, was identified as the causative pathogen of an outbreak of viral pneumonia in Wuhan, China. The disease later named corona virus disease 2019 (COVID-19), subsequently spread across the globe rapidly. Nano-particles and viruses are comparable in size, which serves to be a major advantage of using nano-material in clinical strategy to combat viruses. Nanotechnology provides novel solutions against zoonotic viruses by providing cheap and efficient detection methods, novel, and new effective rapid diagnostics and therapeutics. The prospective of nanotechnology in COVID 19 is exceptionally high due to their small size, large surface-to-volume ratio, susceptibility to modification, intrinsic viricidal activity. The nano-based strategies address the COVID 19 by extending their role in i) designing nano-materials for drug/vaccine delivery, ii) developing nano-based diagnostic approaches like nano-sensors iii) novel nano-based personal protection equipment to be used in prevention strategies.This review aims to bring attention to the significant contribution of nanotechnology to mitigate against zoonotic viral pandemics by prevention, faster diagnosis and medication point of view.


Assuntos
COVID-19 , Preparações Farmacêuticas , Animais , Humanos , Nanotecnologia , Estudos Prospectivos , SARS-CoV-2
8.
Environ Res ; 200: 111428, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34107284

RESUMO

Atrazine is a toxic herbicide whose alarming rate of contamination in the drinking water and wastewater poses a severe threat to the environment and human health. Here in this study, the graphene oxide (GO) nanosheets were prepared using Hummers' method with minor modification and studied as a potential adsorbent for atrazine removal from simulated wastewater. The spectroscopy and microscopic analysis confirmed the successful formation of GO with a multilayer structure resembling the crumpled sheets with random stacking. The Response Surface Methodology (RSM) employing Box Behnken design (BBD) was successfully developed to predict the optimal conditions for maximal atrazine removal as adsorbent dosage 121.45 mg/L; initial feed concentration 27.03 mg/L; temperature 27.69 °C, pH 5.37, and time 180 min. The atrazine adsorption onto GO was found to be higher in acidic pH and lower temperature. Density functional theory (DFT) calculation of adsorbent-adsorbate complex in the implicit solvent medium suggests adsorption affinity energy of -24.4 kcal/mol for atrazine. A careful observation of the molecules configuration and binding energy showed that the π-π interactions and hydrogen bonds played a significant role in the adsorption phenomena. Langmuir isotherm suited well to the adsorption process with a maximum adsorption capacity of 138.19 mg/g, at 318 K. The fitness of kinetic models for atrazine adsorption onto GO nanosheets were in following order Ho < Sobkowsk-Czerwi < Avrami model based on their correlation coefficient (R2) values. Reusability analysis showed that GO nanosheets could be effectively recycled using 0.01 N NaOH up to six cycles of atrazine removal. Thus, this study provided a theoretical and experimental basis for the potential application of GO nanosheets as a novel adsorbent for the removal of hazardous atrazine.


Assuntos
Atrazina , Poluentes Químicos da Água , Adsorção , Teoria da Densidade Funcional , Grafite , Humanos , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análise
9.
J Immunol ; 201(6): 1692-1704, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30061199

RESUMO

The C/EBPα transcription factor is required for myelopoiesis, with prior observations suggesting additional contributions to B lymphopoiesis. Cebpa expression is evident in common lymphoid progenitor (CLP) and preproB cells but is absent in proB and preB cells. We previously observed that marrow lacking the Cebpa +37 kb enhancer is impaired in producing B cells upon competitive transplantation. Additionally, a Cebpa enhancer/promoter-hCD4 transgene is expressed in B/myeloid CFU. Extending these findings, pan-hematopoietic murine Cebpa enhancer deletion using Mx1-Cre leads to expanded CLP, fewer preproB cells, markedly reduced proB and preB cells, and reduced mature B cells, without affecting T cell numbers. In contrast, enhancer deletion at the proB stage using Mb1-Cre does not impair B cell maturation. Further evaluation of CLP reveals that the Cebpa transgene is expressed almost exclusively in Flt3+ multipotent CLP versus B cell-restricted Flt3- CLP. In vitro, hCD4+ preproB cells produce both B and myeloid cells, whereas hCD4- preproB cells only produce B cells. Additionally, a subset of hCD4- preproB cells express high levels of RAG1-GFP, as seen also in proB cells. Global gene expression analysis indicates that hCD4+ preproB cells express proliferative pathways, whereas B cell development and signal transduction pathways predominate in hCD4- preproB cells. Consistent with these changes, Cebpa enhancer-deleted preproB cells downmodulate cell cycle pathways while upregulating B cell signaling pathways. Collectively, these findings indicate that C/EBPα is required for Flt3+ CLP maturation into preproB cells and then for proliferative Cebpaint B/myeloid preproB cells to progress to Cebpalo B cell-restricted preproB cells and finally to Cebpaneg proB cells.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/imunologia , Diferenciação Celular/imunologia , Linfopoese/imunologia , Células Progenitoras Mieloides/imunologia , Células Precursoras de Linfócitos B/imunologia , Animais , Proteínas Estimuladoras de Ligação a CCAAT/genética , Antígenos CD4/genética , Antígenos CD4/imunologia , Diferenciação Celular/genética , Humanos , Linfopoese/genética , Camundongos , Camundongos Transgênicos , Células Progenitoras Mieloides/citologia , Células Precursoras de Linfócitos B/citologia
11.
J Cell Sci ; 129(9): 1928-39, 2016 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27006116

RESUMO

Complement activation has long been associated with inflammation, primarily due to the elaboration of the complement anaphylotoxins C5a and C3a. In this work, we demonstrate that the phagocytosis of complement-opsonized particles promotes host inflammatory responses by a new mechanism that depends on the terminal complement components (C5b-C9). We demonstrate that during the phagocytosis of complement-opsonized particles, the membrane attack complex (MAC) of complement can be transferred from the activating particle to the macrophage plasma membrane by a 'bystander' mechanism. This MAC-mediated bystander damage initiates NLRP3 inflammasome activation, resulting in caspase-1 activation and IL-1ß and IL-18 secretion. Inflammasome activation is not induced when macrophages phagocytize unopsonized particles or particles opsonized with serum deficient in one of the terminal complement components. The secretion of IL-1ß and IL-18 by macrophages depends on NLRP3, ASC (also known as PYCARD) and caspase-1, as macrophages deficient in any one of these components fail to secrete these cytokines following phagocytosis. The phagocytosis of complement-opsonized particles increases leukocyte recruitment and promotes T helper 17 cell (TH17) biasing. These findings reveal a new mechanism by which complement promotes inflammation and regulates innate and adaptive immunity.


Assuntos
Efeito Espectador/imunologia , Complemento C3a/imunologia , Complemento C5a/imunologia , Complexo de Ataque à Membrana do Sistema Complemento/imunologia , Macrófagos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Células Th17/imunologia , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/imunologia , Efeito Espectador/genética , Proteínas Adaptadoras de Sinalização CARD , Complemento C3a/genética , Complemento C5a/genética , Complexo de Ataque à Membrana do Sistema Complemento/genética , Células HEK293 , Humanos , Interleucina-18/genética , Interleucina-18/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Fagocitose/genética
12.
Cancer Immunol Immunother ; 67(10): 1491-1503, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30030559

RESUMO

High-grade gliomas harbor abundant myeloid cells that suppress anti-tumor immunity and support tumor growth. Targeting transcription factors, such as NF-κB p50, that mediate suppressive myeloid M2 polarization may prove therapeutic. GL261-Luc glioblastoma cells were inoculated into wild-type and p50-/- mice, followed by analysis of tumor growth, survival, tumor myeloid cells, and T cells. The absence of host p50 slows tumor growth and enables regression in 30% of recipients, leading to prolonged survival. Tumors developing in p50-/- mice possess a greater concentration of tumor-infiltrating myeloid cells (TIMs) than those in wild-type mice. TIMs are predominantly F4/80hi macrophages which, along with tumor-associated microglia, express increased pro-inflammatory M1 and reduced immune-suppressive M2 markers. In p50-/- mice, total tumor CD4 T cells are threefold more abundant, whereas CD8 T-cell numbers are unchanged, and both produce increased IFNγ and Granzyme B. Naïve splenic p50-/- CD8 T cells manifest increased activation, whereas naïve p50-/- and WT CD4 T cells show similar Th1, Th2, and Th17 polarization. Antibody targeting CD4, but not CD8, fully obviates the p50-/- survival advantage. Combined CD4 and CD8 T-cell depletion reverses myeloid M2 polarization in wild-type hosts, without affecting myeloid M1 polarization in p50-/- hosts. Finally, gliomas grow similarly in p50(f/f) and p50(f/f);Lysozyme-Cre mice, the latter having reduced p50 specifically in myeloid cells and tumor microglia. Thus, high-grade glioma T cells play a key role in directing M2 polarization of tumor myeloid cells, and reducing NF-κB p50 in both tumor myeloid cells and T cells may contribute to glioma therapy.


Assuntos
Glioblastoma/prevenção & controle , Macrófagos/imunologia , Células Mieloides/imunologia , Subunidade p50 de NF-kappa B/fisiologia , Linfócitos T/imunologia , Animais , Células Cultivadas , Glioblastoma/imunologia , Glioblastoma/mortalidade , Ativação Linfocitária , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/metabolismo , Taxa de Sobrevida , Linfócitos T/metabolismo
13.
Cytokine ; 112: 27-31, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30145061

RESUMO

Leishmania is an obligate intracellular parasite uses low pH phagolysosomal compartments of host macrophages as their final abode. IL-1ß is a pro inflammatory cytokine, which is secreted by immune cells to trigger inflammation and this has been found profoundly in the lesions caused by Leishmania pathogens. But the specific role of this cytokine on host cell macrophages during infection has not been fully explored. Here in, we have showed that prolonged exposure of IL-1ß on macrophages increases the parasite burden. Pre-treatment of bone marrow derived macrophages (BMDM) with IL-1ß also generates significantly higher amount of anti-inflammatory cytokine IL-10. As IL-10 plays crucial role in the establishment of infection, enhanced production of IL-10 observed upon IL-1ß treatment could contribute to the progression of the disease. By quantifying the production of Nitric oxide (NO), we further report that the pretreatment of IL-1ß fails to produce the nitric oxide. By measuring the footpad thickness in two different mice strains of differential susceptibility we showed IL-1ß treatment increases parasitic burden. As our results shows that the exposure of IL-1ß helps in disease progression, IL-1ß signalling may be an attractive target for future therapeutic intervention.


Assuntos
Inflamação/imunologia , Interleucina-1beta/metabolismo , Leishmaniose/imunologia , Animais , Medula Óssea/imunologia , Medula Óssea/parasitologia , Feminino , Humanos , Inflamação/parasitologia , Interleucina-10/imunologia , Leishmania/imunologia , Leishmaniose/parasitologia , Macrófagos/imunologia , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Monócitos/parasitologia , Óxido Nítrico/imunologia
14.
Endocr Pract ; 24(2): 205-219, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29466062

RESUMO

OBJECTIVE: Individuals with diabetes are increasingly seeking pretravel advice, but updated professional recommendations remain scant. We performed a systematic review on diabetes management during air travel to summarize current recommendations, assess supporting evidence, and identify areas of future research. METHODS: A systematic review of the English literature on diabetes management during air travel was undertaken utilizing PubMed and MEDLINE. Publications regarding general travel advice; adjustment of insulin and noninsulin therapies; and the use of insulin pumps, glucometers and subcutaneous glucose sensors at altitude were included. Gathered information was used to create an updated summary of glucose-lowering medication adjustment during air travel. RESULTS: Sixty-one publications were identified, most providing expert opinion and few offering primary data (47 expert opinion, 2 observational studies, 2 case reports, 10 device studies). General travel advice was uniform, with increasing attention to preflight security. Indications for oral antihyperglycemic therapy adjustments varied. There were few recommendations on contemporary agents and on nonhypoglycemic adverse events. There was little consensus on insulin adjustment protocols, many antedating current insulin formulations. Most publications advocated adjusting insulin pump time settings after arrival; however, there was disagreement on timing and rate adjustments. Glucometers and subcutaneous glucose sensors were reported to be less accurate at altitude, but not to an extent that would preclude their clinical use. CONCLUSION: Recommendations for diabetes management during air travel vary significantly and are mostly based on expert opinion. Data from systematic investigation on glucose-lowering medication adjustment protocols may support the development of a future consensus statement. ABBREVIATIONS: CSII = continuous subcutaneous insulin infusion (device) DPP-4 = dipeptidyl peptidase 4 EGA = error grid analysis GDH = glucose dehydrogenase GOX = glucose oxidase GLP1 = glucagon-like peptide-1 NPH = neutral protamine Hagedorn SGLT2 = sodium-glucose cotransporter-2.


Assuntos
Viagem Aérea , Diabetes Mellitus Tipo 2/tratamento farmacológico , Prática Clínica Baseada em Evidências , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Guias de Prática Clínica como Assunto , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Automonitorização da Glicemia , Diabetes Mellitus Tipo 2/sangue , Prática Clínica Baseada em Evidências/normas , Humanos , Sistemas de Infusão de Insulina
15.
Undersea Hyperb Med ; 45(1): 75-82, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29571235

RESUMO

INTRODUCTION: In April 2016 the Association of Diving Contractors International (ADCI) consensus guidelines began recommending annual cardiovascular risk stratification of commercial divers using the Framingham Risk Score (FRS). For those at elevated risk, further testing is recommended. This approach has raised concerns about potential operational and financial impacts. However, the prevalence of elevated cardiovascular risk and need for additional testing among commercial divers is not known. METHODS: Clinical data required to calculate the FRS was abstracted for 190 commercial divers in two cohorts. Population demographics, FRS distribution, contributions of risk factors and effect of interventions on reducing risk-factor burden were assessed. RESULTS: Mean FRS score was 1.68 ± 6.35 points, with 13 divers (6.8%) at intermediate risk and none at high 10-year risk. In these 13 divers, the mean contributions to the FRS were from age (6.5 points), cholesterol (3.1 pts.), smoking (1.3 pts.), highdensity lipoprotein (1 pt.), and systolic blood pressure (0.8 pts). The youngest age group had a significantly higher modifiable risk core than the oldest age group (5.87 vs. 1.2 points, P ⟨ 0.001). All 13 intermediate risk divers could have been reclassified as low-risk with successful treatment of modifiable risk factors. DISCUSSION: The prevalence of elevated cardiovascular risk among commercial divers is low, and treatment of modifiable risk factors could reclassify those at intermediate risk to low risk. Therefore, FRS implementation coupled with intensive risk-reduction strategies for at risk-divers may help improve diver health and prolong the careers of divers while limiting the need for additional testing and adverse operational impact.


Assuntos
Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Mergulho/efeitos adversos , Doenças Profissionais/etiologia , Doenças Profissionais/prevenção & controle , Medição de Risco , Adulto , Fatores Etários , Pressão Sanguínea/fisiologia , Colesterol/sangue , Feminino , Humanos , Lipoproteínas HDL/sangue , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sexuais , Fumar/efeitos adversos
16.
Nucleic Acids Res ; 43(14): 6799-813, 2015 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-26150419

RESUMO

Protozoan parasites of the genus Leishmania are the etiological agents of leishmaniasis, a group of diseases with a worldwide incidence of 0.9-1.6 million cases per year. We used RNA-seq to conduct a high-resolution transcriptomic analysis of the global changes in gene expression and RNA processing events that occur as L. major transforms from non-infective procyclic promastigotes to infective metacyclic promastigotes. Careful statistical analysis across multiple biological replicates and the removal of batch effects provided a high quality framework for comprehensively analyzing differential gene expression and transcriptome remodeling in this pathogen as it acquires its infectivity. We also identified precise 5' and 3' UTR boundaries for a majority of Leishmania genes and detected widespread alternative trans-splicing and polyadenylation. An investigation of possible correlations between stage-specific preferential trans-splicing or polyadenylation sites and differentially expressed genes revealed a lack of systematic association, establishing that differences in expression levels cannot be attributed to stage-regulated alternative RNA processing. Our findings build on and improve existing expression datasets and provide a substantially more detailed view of L. major biology that will inform the field and potentially provide a stronger basis for drug discovery and vaccine development efforts.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Leishmania major/genética , Processamento Pós-Transcricional do RNA , Perfilação da Expressão Gênica , Ontologia Genética , Genes de Protozoários , Leishmania major/crescimento & desenvolvimento , Leishmania major/metabolismo , Poliadenilação , Análise de Sequência de RNA , Trans-Splicing
17.
BMC Genomics ; 16: 1108, 2015 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-26715493

RESUMO

BACKGROUND: Parasites of the genus Leishmania are the causative agents of leishmaniasis, a group of diseases that range in manifestations from skin lesions to fatal visceral disease. The life cycle of Leishmania parasites is split between its insect vector and its mammalian host, where it resides primarily inside of macrophages. Once intracellular, Leishmania parasites must evade or deactivate the host's innate and adaptive immune responses in order to survive and replicate. RESULTS: We performed transcriptome profiling using RNA-seq to simultaneously identify global changes in murine macrophage and L. major gene expression as the parasite entered and persisted within murine macrophages during the first 72 h of an infection. Differential gene expression, pathway, and gene ontology analyses enabled us to identify modulations in host and parasite responses during an infection. The most substantial and dynamic gene expression responses by both macrophage and parasite were observed during early infection. Murine genes related to both pro- and anti-inflammatory immune responses and glycolysis were substantially upregulated and genes related to lipid metabolism, biogenesis, and Fc gamma receptor-mediated phagocytosis were downregulated. Upregulated parasite genes included those aimed at mitigating the effects of an oxidative response by the host immune system while downregulated genes were related to translation, cell signaling, fatty acid biosynthesis, and flagellum structure. CONCLUSIONS: The gene expression patterns identified in this work yield signatures that characterize multiple developmental stages of L. major parasites and the coordinated response of Leishmania-infected macrophages in the real-time setting of a dual biological system. This comprehensive dataset offers a clearer and more sensitive picture of the interplay between host and parasite during intracellular infection, providing additional insights into how pathogens are able to evade host defenses and modulate the biological functions of the cell in order to survive in the mammalian environment.


Assuntos
Interações Hospedeiro-Patógeno/genética , Leishmania major/fisiologia , Macrófagos/metabolismo , Animais , Perfilação da Expressão Gênica , Leishmania major/genética , Camundongos , Transcriptoma/genética
18.
J Mol Cell Cardiol ; 74: 13-21, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24801707

RESUMO

BACKGROUND: Whole-genome gene expression analysis has been successfully utilized to diagnose, prognosticate, and identify potential therapeutic targets for high-risk cardiovascular diseases. However, the feasibility of this approach to identify outcome-related genes and dysregulated pathways following first-time myocardial infarction (AMI) remains unknown and may offer a novel strategy to detect affected expressome networks that predict long-term outcome. METHODS AND RESULTS: Whole-genome expression microarray on blood samples from normal cardiac function controls (n=21) and first-time AMI patients (n=31) within 48-hours post-MI revealed expected differential gene expression profiles enriched for inflammation and immune-response pathways. To determine molecular signatures at the time of AMI associated with long-term outcomes, transcriptional profiles from sub-groups of AMI patients with (n=5) or without (n=22) any recurrent events over an 18-month follow-up were compared. This analysis identified 559 differentially-expressed genes. Bioinformatic analysis of this differential gene-set for associated pathways revealed 1) increasing disease severity in AMI patients is associated with a decreased expression of genes involved in the developmental epithelial-to-mesenchymal transition pathway, and 2) modulation of cholesterol transport genes that include ABCA1, CETP, APOA1, and LDLR is associated with clinical outcome. CONCLUSION: Differentially regulated genes and modulated pathways were identified that were associated with recurrent cardiovascular outcomes in first-time AMI patients. This cell-based approach for risk stratification in AMI could represent a novel, non-invasive platform to anticipate modifiable pathways and therapeutic targets to optimize long-term outcome for AMI patients and warrants further study to determine the role of metabolic remodeling and regenerative processes required for optimal outcomes.


Assuntos
Redes e Vias Metabólicas/genética , Infarto do Miocárdio/genética , Transcriptoma , Transportador 1 de Cassete de Ligação de ATP/genética , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Adulto , Idoso , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , Transporte Biológico , Estudos de Casos e Controles , Colesterol/metabolismo , Proteínas de Transferência de Ésteres de Colesterol/genética , Proteínas de Transferência de Ésteres de Colesterol/metabolismo , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Feminino , Seguimentos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Inflamação/diagnóstico , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Prognóstico , Receptores de LDL/genética , Receptores de LDL/metabolismo
19.
Aerosp Med Hum Perform ; 95(5): 278-281, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38715272

RESUMO

BACKGROUND: This article documents the stability of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK) in two astronauts during 6-mo missions to the International Space Station.CASE REPORTS: Ocular examinations including visual acuity, cycloplegic refraction, slit lamp examination, corneal topography, central corneal thickness, optical biometry (axial length/keratometry), applanation tonometry, and dilated fundus examination were performed on each astronaut before and after their missions, and in-flight visual acuity testing was done on flight day 30, 90, and R-30 (30 d before return). They were also questioned regarding visual changes during flight.DISCUSSION: We documented stable vision in both PRK and LASIK astronauts during liftoff, entry into microgravity, 6 mo on the International Space Station, descent, and landing. Our results suggest that both PRK and LASIK are stable and well tolerated during long-duration spaceflight.Gibson CR, Mader TH, Lipsky W, Schallhorn SC, Tarver WJ, Suresh R, Hauge TN, Brunstetter TJ. Photorefractive keratectomy and laser-assisted in situ keratomileusis on 6-month space missions. Aerosp Med Hum Perform. 2024; 95(5):278-281.


Assuntos
Astronautas , Ceratomileuse Assistida por Excimer Laser In Situ , Ceratectomia Fotorrefrativa , Voo Espacial , Acuidade Visual , Humanos , Medicina Aeroespacial , Ceratomileuse Assistida por Excimer Laser In Situ/métodos , Miopia/cirurgia , Miopia/fisiopatologia , Ceratectomia Fotorrefrativa/métodos , Acuidade Visual/fisiologia
20.
J Allergy Clin Immunol Glob ; 3(2): 100244, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38577482

RESUMO

A case report detailing, for the first time, a case of laboratory-confirmed zoster in an astronaut on board the International Space Station is presented. The findings of reduced T-cell function, cytokine imbalance, and increased stress hormones which preceded the event are detailed. Relevance for deep space countermeasures is discussed.

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